Black Cutworm moths are starting to arrive in the Corn Belt with the recent weather fronts moving from southwest and we need to be ready with the rescue treatments if necessary. We need to learn about their habits and what to look for while scouting. Some of the important points about its habits are given below:
• Black cutworms can’t survive the winters in the Midwest. They fly south before the winter arrives.
• Every spring, moths come back with spring storms and lay eggs on grasses, weeds like mustards, chickweed or even winter wheat.
• It takes 40-50 days from egg-hatching to becoming adults. Their development depends on temperature and moisture. Warmer temperatures speed up their development.
• Corn and soybeans are not their favorite hosts. When weeds are destroyed, larvae start feeding on corn. Small larvae feed on leaves. If you see small, irregular holes in the leaves, start looking for cutworms.
• They feed above ground until they are about half inch long. It takes three instars for black cutworms to get to that stage. Each instar needs 100- 140 growing degrees.
• After about 300-400 accumulated GD, at the fourth instar, watch out! Now these enemies of our corn crop are ready to do real damage and start cutting plants at or below ground level.
• Black cutworms are clever insects. They hide during the day and feed at night. Scout your fields at least once a week and attack the enemy with suitable foliar insecticides, if necessary, otherwise they can do serious damage to your crops.
As the growing season progresses, we will discuss the major diseases and insect pests in this space so you can take effective measures and protect your crops.